Silk Protein Evolution and Spider Phylogenetics: an EST Approach

加州大学河滨分校（University of California, Riverside）的谢丽尔·哈亚希（Cheryl Hayashi）博士获得了一笔拨款，用于研究蜘蛛及其丝蛋白的进化。球织蜘蛛的拖丝作为生物材料被高度重视，因为这些基于蛋白质的纤维具有非凡的强度和韧性。大多数关于拖丝的知识来自于对两个物种的研究。已知的蜘蛛种类超过34000种，除了拖丝外，大多数蜘蛛还会纺多种类型的丝，因此蜘蛛丝的多样性令人难以置信。实际上，我们对蜘蛛丝的机械特性和基因知之甚少。Hayashi博士的第一个目标是记录蜘蛛丝广泛的分子和生物力学变化。为了做到这一点，她将对不同种类的蜘蛛所纺的丝纤维进行拉伸测试，然后克隆在丝腺组织中表达的基因转录本。她研究的第二个目标是追踪蜘蛛进化过程中丝基因序列的变化。这项工作包括根据DNA序列重建蜘蛛的系统发育历史。为了完成她的研究目标，林博士将培养一名博士后科学家和一名研究生。此外，加州大学河滨分校的本科生将参与小型独立项目，这些项目将在一到两个学期内完成。Hayashi博士的研究成果将推进蛛丝蛋白和蜘蛛进化的知识状态，并将显著扩大蜘蛛DNA序列的国际数据库。这项工作也与正在开发的大规模生产人造蜘蛛丝的商业技术有关。将丝纤维性能与特定丝基因序列联系起来的相关数据对于设计新型生物材料至关重要。

Dr. Cheryl Hayashi at the University of California, Riverside has received a grant to study the evolution of spiders and their silk proteins. The dragline silks of orb-weaving spiders are highly prized as biomaterials because these protein-based fibers have remarkable combinations of strength and toughness. Most knowledge of dragline silks comes from studies done on two species. With over 34,000 described species, and with most species spinning multiple types of silks in addition to the dragline, spider silks are incredibly diverse. Very little is actually known about the mechanical properties and genetics of spider silks. Dr. Hayashi's first goal is to document the extensive molecular and biomechanic variation of spider silks. To do this, she will perform tensile tests of silk fibers spun by different species of spiders, and will then clone the gene transcripts that are expressed in silk gland tissue. The second goal of her study is to trace how silk gene sequences have changed as spiders evolved. This work involves reconstructing the phylogenetic history of spiders from DNA sequences.To accomplish her research objectives, Dr. Hayashi will train a postdoctoral scientist and a graduate student. In addition, undergraduate students at the University of California, Riverside will participate through small, independent projects that are designed to be completed within one or two academic quarters. The results of Dr. Hayashi's studies will advance the state of knowledge of silk proteins and spider evolution, and will significantly enlarge the international database of spider DNA sequences. The work is also relevant to commercial technologies that are being developed to mass-produce artificial spider silk. Correlational data that link performance of silk fibers to specific silk gene sequences are critical for the design of novel biomaterials.